Iran might be “on the verge of producing weapon-quality plutonium,” Germany’s daily Die Weltreported on Nov. 26. Hans Rühle, a former top official in the German defense ministry, and foreign editor Clemens Wergin cite clues pointing to an Iranian crash program to build a plutonium bomb in the just-released International Atomic Energy Agency report on Iran’s nuclear activity. Rühle headed German defense policy planning during the 1980s; Wergin is one of the most capable young journalists writing in any language. Their report should be read in dead earnest.

The IAEA reported that Iran removed fuel rods from the Bushehrlight water reactor—supposedly a peaceful application of nuclear energy—on October 22. There might be a technical explanation for the premature extraction of fuel rods from a light water reactor, Rühle and Wergin observe. But “it may also mean the starting point for production of weapons-grade plutonium. That would mean a dramatic expansion and acceleration of Iran’s nuclear armaments program (my translation).”

Although light water reactors are not designed to produce weapons-grade plutonium, the design can produce large amounts of weapons-grade plutonium in a short period of time. In a matter of months, the authors report, the low-enriched uranium fuel in the Bushehr reactor could yield enough plutonium for dozens of atomic bombs:

In a light water reactor, which is operated with low enriched uranium (four percent), the fuel remains in the reactor up to 60 months when the reactor is run at maximum power generation,. But it takes only a few months to produce plutonium 239, that is, weapons-grade plutonium. … In the 1970s a British company had shut down a light water reactor prematurely. The result was around 450 kilograms of plutonium, or material for about 70 bombs.

It would take only three or four months to convert the plutonium from the Bushehr reactor’s spent fuel rods into weapons-grade plutonium, the authors report. Depending on how long the fuel rods were used before Iran removed them on Oct. 22, they would yield between 150 kg and 300 kg of plutonium, or enough fissile material for 25 to 50 bombs.

Western negotiators previously ignored the Bushehr reactor, on the grounds that it constituted peaceful use of energy. Oliver Thränert, head of the Center for Security Studies at ETH Zurich, told Die Welt, “If Iran does not give a convincing explanation for the early removal of fuel rods, a correction in this policy should be urgently considered.”

Last February, I cited Rühle’s analysis of the logistics of a possible Israel strike on Iran, in which the German expert argued that Israel had the capacity to set the program back by years.